Tire Ruler275/70R18 dimensions
| Overall diameter (height) | 33.16″ · 842 mm |
| Section width | 10.83″ · 275 mm |
| Sidewall height | 7.58″ · 193 mm |
| Wheel diameter | 18″ |
| Rim width (rule of thumb) | 7.5–9.5″ |
| Circumference | 104.2″ |
| Revolutions per mile | 608 |
| In inches (flotation style) | 33.2 × 10.8R18 |
How it’s calculated: the sidewall is 70% of the 275 mm width = 192.5 mm (7.58″). Add two sidewalls to the 18″ wheel: 18 + 2 × 7.58 = 33.16″.
Bigger tires than 275/70R18 on 18″ wheels
| Size | Height | Taller by | 60 mph reads |
|---|---|---|---|
| 295/70R18 | 34.3″ | +1.10″ (+3.3%) | 62.0 mph |
| 325/65R18 | 34.6″ | +1.48″ (+4.5%) | 62.7 mph |
| 285/75R18 | 34.8″ | +1.67″ (+5.0%) | 63.0 mph |
| 35x12.50R18 | 35.0″ | +1.84″ (+5.6%) | 63.3 mph |
“60 mph reads” is your real speed when a speedometer set up for 275/70R18 shows 60. Above about 3% taller, most trucks need a leveling kit or lift, and the speedometer should be recalibrated.
Sizes equivalent to 275/70R18
Within 1.5% of the same height on an 18″ wheel. Usually interchangeable for the speedometer; check width, load index and clearance.
| Size | Height | Width | Difference |
|---|---|---|---|
| 33x12.50R18 | 33.0″ | 12.5″ | −0.5% |
Same height on a different wheel size
Changing wheel size (plus or minus sizing) while keeping the overall height keeps your speedometer right:
- 33x12.50R15: 33.0″ tall on a 15″ wheel (−0.5%)
- 285/75R16: 32.8″ tall on a 16″ wheel (−1.0%)
- 285/70R17: 32.7″ tall on a 17″ wheel (−1.4%)
- 295/70R17: 33.3″ tall on a 17″ wheel (+0.3%)
- 255/80R17: 33.1″ tall on a 17″ wheel (−0.3%)
- 33x12.50R17: 33.0″ tall on a 17″ wheel (−0.5%)
- 275/60R20: 33.0″ tall on a 20″ wheel (−0.5%)
- 285/60R20: 33.5″ tall on a 20″ wheel (+0.9%)
- 305/55R20: 33.2″ tall on a 20″ wheel (+0.2%)
- 295/55R20: 32.8″ tall on a 20″ wheel (−1.2%)
- 265/65R20: 33.6″ tall on a 20″ wheel (+1.2%)
- 33x12.50R20: 33.0″ tall on a 20″ wheel (−0.5%)
- 305/45R22: 32.8″ tall on a 22″ wheel (−1.1%)
- 275/50R22: 32.8″ tall on a 22″ wheel (−1.0%)
- 33x12.50R22: 33.0″ tall on a 22″ wheel (−0.5%)
Popular 275/70R18 comparisons
Frequently asked questions
Is 275/70R18 a 33 inch tire?
Yes. 275/70R18 is 33.16 inches tall, so it's sold and talked about as a 33-inch tire.
What size is 275/70R18 in inches?
275/70R18 is 33.2 inches tall (overall diameter), 10.8 inches wide, with a 7.6 inch sidewall, and fits an 18 inch wheel.
What tire size is equivalent to 275/70R18?
Sizes within 1.5% of the same diameter on an 18" wheel: 33x12.50R18 (33.0"). Check load index and width before swapping.
What rim width fits 275/70R18?
As a rule of thumb, about 7.5–9.5 inches. The tire maker's spec sheet lists the approved range for each model.
How many revolutions per mile does 275/70R18 make?
About 608 revolutions per mile in theory (circumference 104.2 in). Real tires turn slightly more because they flatten under load.